He unlocked the Lopez serve for a third time on the back of two wonderful shots. First, a superb passing return set up break point, which he converted with a perfect lob to the back of the court.

Murray wobbled briefly when serving for the match at 5-2, allowing Lopez a first break of the contest, but he held in his next service game to get over the line.

A rested world number one now lies in wait after Djokovic progressed without hitting a ball due to the withdrawal of Australian 32nd seed Tomic, who has a back injury.

However, Murray told BBC Sport: "I don't want to talk about advantages or disadvantages. When we start the match on Saturday both of us should be fairly fresh."

"If I play at the level I've been playing so far, I'll give myself a chance, but it's tougher to maintain the highest possible levels against the best players," he added. "It'll be a good test for me and one I'm looking forward to."

Asked if his progress in the tournament to date was satisfactory in itself, Murray cited significant progress from last year.

"If you expect to win every tournament, you'll never get any enjoyment out of the sport because it's tough to win every week. No-one does. Even the best players in the world are losing 14 or 15 games a year," he said.

"If I lose, I'll be disappointed but you can still look back on a tournament you haven't won and be happy. So far this has been big progress from where I was at this stage last year."